Aqueous dispersions of vulcanized fatty oils



Patented Jan. 6, 1948 2,435831 decreesnisriinsionsbii FATTY OILS Laszlofiiier; South orangefNfJ.

' No Drawin'g. Application Serial No. 467,-905 scrai'fns. (01. 2 52- 312) Field of invention and objects This invention relates to new and improved products inthe form of aqueous dispersions or emulsions of vulcanized fatty oils, andli's particularly concerned with productsof this general type having characteristics similar "to rubber latex emulsions. V

Vulcanized oils (known as facticefhavebeen employed for various purpose's' 'heretofore, and quite a wide variety of such vulcanized oils have been made. i In general, such prior vulcanized oils-merely comprise a fatty oil to which sulphur has beemaddedgthe mixture being heated to efiect thevulcanization. c T

It has further" been proposed to emulsiiy or formaqueousdispersions of various of the known vulcanized fatty oils, although such aqueous dispersions, in general, -have heretofore been prepared" primarily; from partially vulcanized fatty oils, because of the difficultyfiofdispersing fully vulcanized; oils. I have found, however, that especially advantageous properties are secured from an aqueous dispersion or emulsion of fully vul- (:anizedfatty oils of a certain class hereinafter S/ defined, apdiurthen that said particular class of fully vulcanized fatty oils are more readilydisper's'ed than other types of fully vulcanized o'ils.

At this point, hwever} I desire tornake it near if heatingbe terminated, the products "are li'quidat i oom' temperatur or are" reversibly fusibleantithermoplastic; Furthermore, the entireina'ss of the mixture" may besoluble fineertain organic solvents. Products ot'thiedegr'ee of vulcanization are herein' considered-as partiallyf er' semi-vulcanized products. I

If the vulcanization be carried further; by contitiued heating solid mass is fdrr'ned atftl'ie vulcanization"temperature, whichmass is in fusible (except upon decompositionl -"ancl the mass :asga 'whole :is insoluble in organic solvents.

Products having. thisdegreje of vulcanization are herein con sidered as iullyf or completely vulin some cases 'futther solidification V might'be -ef-' fected by" continued-heating beyondthe time at which-the infusible mass is :initially formed.

Before continuing this. specification itmay be further noted "that alth'oughtheterm emulsion is sometimes appliedonly toithat classof colloidal dispersions wherein "both the dispersed phase; and-dispersion' medimn are; liquid; in technicalliterature the term emulsion, is quite commonly-applied to-that'typ'etof dispersion-in which the dispersed phase-isa solidmaterial; so long as the dispersion displays the generalnaturejand behavior ofrliquid-iiquid emulsions. "Thus, for instance, rubber latex, is commonly; referred to as an mulsion, in spite of the fact that the rubber particles mane-latex are-solid. It is to be "u n'd'erstoodthathereinthe; term emul'siorr is not employed in the"narrowsenseibutisused to apply to bbth types of dispersion.

Fully vulcanized fatty 'oils in "aqueous- "dispersions,l'where"the fatty'oiris-of arce'rtain" definite type identified hereinafter, yield dispersion products' having characteristics which are more like those of rubber;-than are dispersions of partially vulcanized fatty oils, or dispersions of 'ce'rtain other-typesf of fully "vulcanized fattyoils, *although' I believe that .few'if-"any ofth'e latter type have" been; satisfactorily" produced. V

Briefly; the vulcanized oil products which I employ accordance with the present invention: are? products produced by treatment-itprior V to vulcanization)- to incorporate awater soluble produced in accordance with said copendingapcanized products, notwithstanding the fact: that salt- (includingsoapsas salts); such as {a water soluble metal 'soapnproduced in situpwith the fattyacids present, This treatmenfiis" thentfollowed by vulcanization of the fatty oil, "after which the same isdispersed to secure an' emulsion of the oil-inewater 1type. As an exampleof the type of vulcanized; fatty oil employed; reference ismade to the vulcanized fatty oilxproducts produced in accordance with thepdisclosllre of myqcopend-ing application, Serialv No. 4395.13,. filed Ami-111.8, 1942. ,In fact, especially desirable and latex-like products are secured by dis-- persion of the particular vulcanized fatty oils plica v, V. pispersions oi fully vulcanized fatty oils incorporating a water soluble salt are much-more readily inade than are dispersions of other fully vulcanized fatty oil products. Such dispersions,-

rties of the dispersions produced according to this invention render the new dispersions capable of effective use in various situations where compatibility with water or capability of dilution with water is an advantage. Vulcanized oil products incorporating a water soluble salt have properties much more like those of rubber than do vulcanized oil: products of other types, since the former have unusually high tensile strength and nerve as well as other rubber-like properties when compounded with rubber. In addition such products are more easily compounded with natural or synthetic rubber. Therefore, the dispersions according to the present invention, containing fully vulcanized fatty oils of the type described, are very useful when employed as rubber extenders, as for instance, by mixing the vulcanized oil dispersions with rubber latex, and/or synthetic rubber latices. Moreover, very good results are secured by employing the dispersions in coatings to be applied to porous surfaces, made of paper, stucco, wood, plaster, cement, etc., such as walls and/or floors. Still further, emulsions of the roofing compound type may advantageously be prepared to contain both an asphalt and a vulcanized fatty oil dispersed in water according to this invention.

Although I prefer to employ a dispersion process in accordance with my copending application Serial No. 467,904, filed concurrently herewith (now Patent 2,382,532, issued on August 14, 1945), the dispersion may be produced in other ways, several suitable procedures for dispersion being referred to more fully hereinafter.

The class of vulcanized fatty oils As above indicated, the process of this invention is applicable to fully vulcanized fatty oils of certain types. In general, the vulcanized fatty oils which are usable .in accordance with the present invention are fully vulcanized fatty oils incorporating, by treatment prior to vulcanization, a water soluble salt, such for instance, as a salt formed with fatty acid present by addition of sodium hydroxide.

In addition to the employment of fully vulcanized fatty oil products of the type produced in accordance with the copending application identified above, which is preferred in accordance with the invention, somewhat similar dispersion products may be obtained by employing fully vulcanized fatty oil products incorporating a watersoluble salt, as produced in accordance with certain other prior patents, including my prior Patents 1,985,230, 1,957,437, 2,234,949, 2,189,772, 2,213,944, 2,298,270.

Various of the prior disclosures above mentioned provide for the production of a vulcanized fatty oil product by adding (prior to vulcanization) a water-soluble metal compound such as an alkali metal compound, for instance, an alkali metal hydroxide. Treatment of this type produces a vulcanized oil product useable in accordance with the present invention, the treatment resulting in the'production in situ of a water-soluble soap by reaction of the alkali metal hydroxide with fatty acids present. Water soluble ammonium salts added as such or produced in situ are also useable, these being classed with the alkali metal salts for the present purposes, since their behavior is similar.

Certain other prior disclosures mentioned above provide for treatment of the oil (prior to vulcanization) to incorporate or produce in situ water-soluble organic compounds such, for instance, as amine soaps. Products useable in accordance with the invention are also secured by this treatment.

Many of such treatments produce a. watersoluble salt (including soaps) in situ, as a result of reaction with fatty acids present, this being important from the standpoint of the present invention. Such salts may be added directly, rather than being formed in situ.

As far as the fatty oil itself is concerned, fatty oils generally are useable.

A typical list of such fatty oils is as follows:

'Tung oil Oiticica oil Dehydrated castor oil Linseed oil Perilla oil Poppyseed oil Soya bean oil Walnut oil Rapeseed oil Pine seed oil Olive oil Corn oil Cottonseed oil Coconut oil Babassu oil Hydroxylated oils such as castor oil, etc.

Fish oils (train oils) In addition, it should-be noted that esters of fatty acids other than the natural glycerin esters (fatty oils) may be used, for example, synthetic glycerin esters of fatty acids, and fatty acid esters formed with other polyhydric alcohols, such as glycols, pentaerythritol, mannitol, sorbitol, etc.

Certain other materials heretofore compounded with vulcanized oils may be combined with the fully vulcanized fatty oil prior to dispersion.

It may be mentioned that somewhat different emulsion products may, of course, be secured by the employment of different oils, so that the oils selected will depend on a number of factors, such as the characteristics desired in the emulsion.

Linseed oil, soya bean oil and fish oils are especially desirable, also sunflower, rapeseed, corn and cottonseed oils are important.

Illustrative process There is given just below an illustrative process for producing a fully vulcanized fatty oil product suitable for dispersion according to the invention, this illustrative process also being disclosed in my copending application Serial No. 439,513, above mentioned.

Assume that raw linseed oil is the primary starting material selected. The procedure may then be summarized as follows (the quantities mentioned in the several steps indicating proportions of materials, it being understood that a batch of any desired size may be carried through the process) (1) 8014 gms. of raw linseed oil are heated in a 22 liter distilling flask up to 300 C. and the pressure reduced to mm. of mercury; and during temperature rise and for five hours at 300 C., S02 is bubbled through the oil at an even rate ofv 20 gms. an hour.

(2) The vacuum is broken and the bubbling of S02 is maintained on the surface of the batch.

(3) The batch is gently agitated for one-half hour and at the start of this period 106.6 gms. of

, NaOH flakes are added 'tb tlie batch, the temperature still being maintained at 300 C.

. (4); The agitation is terminated andthe reac tion vessel 'is again evacuated, to 'a' pressure just short of that producing foaming, for instance,

400" mm. of mercury, this condition being maintained for'an additional period of one-half hour, still at 300 C.

(5) Application of heat is terminated and the bat'chis allowed to coolto 20076. (requiring about dneandone-half hours), during which time the reducedpressure (400- mm. of mercury) is maintained.

(6)Upon reaching 200 C., the vacuum is broken by admitting air and the batch poured into a vulcanizing kettle.

(7) Upon further coolingto 135 C., a mixture of sulphur, zinc oxide and mercaptobenzothiazole pastes are added (55 0'gms; sulphur paste, 110 gms. ZnO paste" and 64.2 g'ms. mercaptobenzothiazole paste described hereinafter); the batch being vigo'rously ag'itated during this addition, and the temperature-dropping further to about 120 C.

('8) The temperature is then maintained "at about 120 C. to 125 C. until the desired degree of vulcanization has 'takenplace, which may require-from about 2 to 4 hours (calculated from the firsta'ddition of sulphur), depending on the particular batch of oil, the heating conditions, etc Ways of determining when the desired degreeof vulcanization is secured are set out more f-ully'hereinafter.

"(@fTlie vulcanizedi productispoured out to cool and set.

The vulcanized product is dispersed by working the material on a paint mill, for instance of the three-roller type commonly employed'for grinding pigments into paints, at room temperature, the dispersion being effe'cted'in the presence of '16 cc. of an aqueous sodium hydroxide solution (10% strength), together with suificient of a 2% aqueous solution ofmethyl cellulose to give 1% of methyl cellulose in the dispersion (1% on the basis of the content of vulcanized oil).

, The iforegoing processis to be considered as illustrative. Steps 1 to 9 inclusive of said process are subject to variations of the types fully set out in my copending application above referred to. It isnot thought necessary herein to consider in detail all of the possible variations which may be adopted since, for that purpose, reference may behad tosaid copendi'ng application.

A few'of the more important Variables and.

ranges, for instance, rangesof temperatures and percentages are, however, notediustbelow.

Heat bodying As to step 1, it may be mentioned that sulphurcontaining gases other than $02 may be employed, for instance'I-IZS. During the treatment with the sulphur-containing gas, the temperature is desirably keptb'etween about 200C. and 350 C; depending upon the oil being treated and also on other conditions, including especially the quantity'oi S02 which is bubbled through the oil. During the treatment "with the sulphur-contain"- ing as, the oil is heat bodiedto an extent yielding 'a modified, heat bodied oil product: having a, viscosity (at atmospheric pressure) of from abo'utV to 2+6 "on theGardner scale, preferably Z4 to Z-'-5.

With reference'to the addition of flake sodium hydroxide in step 3; it-may be mentioned that assess ii other forms of sodiiim hydroxide may be Moreover, other inorganic bases may be-use'd in place I of scdium hydroxide to produee' watersoluble sans (such as soaps) in sit-u, 'particularly oxides 'or hydroxides offlithium and potassium, oxide of sodium and'hydriixic'le of ammonia.

'When'usi'ng sodiumhydroxide" the quantity is preferably" kept between -.1%' and'5%; and usually between .5% and 2.5%. For equivalent results when other inorganic bases areen'i'pl'o'y'em' they are desirably used in proportions which are chemically equivalent to the ranges lust indicated.

The heating at elevated temperatures," for instance from about 200 C; to about 300 (3., should be continued for a reasonable time after addition of the sodium-hydroxide. for instance for a-period of time "upwards of about one-lialf'ho'ur.

Vulelmiedtion vulcanization (mentioned above in steps 7-and 8 of the illustrated process) is desirably efiected atatemperature between about 110 C. and 180 C., and most" advantageously between about 110 C. and 140 0., the'quant-ity of sulphuradd'ed being from about oneand one-half parts toabout parts for each 100 parts of theheat bodied oil, and the sulphur preferably being added'in paste form, as is' mentioned in step 7 above. Such a sulphur paste is prepared of finely ground sulphur'disp'ersed in linseed oil in the proportions of 2 parts by weight or sulphur tol part by Weight of linseed oil.

When using linseed oil, I prefer a temperature between about 120 C. and 125 C. and from about 7% to-about 12 of sulphur, when acceleratorsare used,alth-oug'h as high as20% may be required in the absence of'ac'celerators.

As indicated in the foregoing illustrative process, other materials, such as accelerators (mercaptobenzothiazole or tetrarnethylthiuram disulfide or others), may if desired be added at the tivator of the accelerator. These additional materia'ls may also be added in the form of pastes,

and when this is done I prefer to conjointly introduc'e thesematerials with the sulphur paste, all three materials being mixed together The zinc oxide paste (110 gms. in the illustrative process) constitutes about 3% of the batch under treatment, the paste being composed of zinc oxide and linseed oil in the proportions of about two parts of the former to'about one part of the latter. The zinc oxide thus constitutes about 2% of the batch under treatment. The 64.2 gins, of mercaptobenzothiazolepaste referred to in the illustrative process constitute about 1.75% of the batch, being composed of 1% Captax and 0.75% linseed oil. I V 7 g In determining the progress of vulcanization, the consistency of the mass is observed; For most purposes, the desired degree of vulcanization is attained when the mass thickens to the degree rendering further agitation diflicult if not impractical. As a further test, a paddle maybe insertedin the mass, and when the mass shows a tendency to break away-from the paddle asit is drawn out, the proper degree of vulcanization has been reached. Still another test which may be used is the placing of sample drops on a fiat surface, such as cardboard, glass or metal plate,

and when such drops, even though 'stickyymay be rolled off with the finger, the vulcanization is sufficient.

The foregoing tests are given since the actual time varies from batch to batch, although with linseed oil treated in accordance with the illustrative process herein fully disclosed, the vulcanization time will frequently fall between about 2 and 4 hours (calculated from the first addition of sulphur). With other oils and with variations of the process in accordance with the above description, the time may be either shorter or longer (for instance, up to seven or even nine hours).

With regard to vulcanization it may be mentioned that the foregoing illustrative process is given only for purposes of illustration. The vulcanization procedure of the illustrative process described above carries the vulcanization of the oil to a fairly advanced stage. For some purposes, when preparing dispersions as herein contemplated, the vulcanization may be terminated at a somewhat earlier stage, provided the product is solid (i. e. fully vulcanized, as herein defined). On the other hand, for certain other purposes the vulcanization may be continued beyond the point provided by the procedure outlined above.

In addition to dispersions made with fatty oils vulcanized with sulphur, dispersions may also be made from so-called white rubber substitutes, i. e., fatty oils which are vulcanized with sulphur chloride, this usually being accomplished at temperatures considerably lower than those employed when employing sulphur.

Dispersion Example 1 From the above it will be noted that in this example the dispersing is effected in the presence of methyl cellulose and sodium hydroxide. This procedure is disclosed more fully in my copending application Serial No. 467,904, filed concurrently herewith (now Patent 2,382,532, issued on August 14, 1945).

As an example of another procedure suitable for effecting dispersion, a methyl cellulose solution may be added to the material while the material is being worked on a paint mill or a kneading machine, without the addition of appreciable quantities of any other wetting agent, such as soaps or soap forming compounds. Thus Example 2 A linseed oil product was pretreated with S02 and with sodium hydroxide, and vulcanized exactly as set out above in steps 1 to 9 inclusive of the illustrative process hereinabove described until a fully vulcanized product was secured. This material was worked on a three-roller paint mill of the type above mentioned at room temperature. During the working a quantity of methyl cellulose in aqueous solution was added in increments, sufficient to incorporate 1% of methyl cellulose, calculated on the basis of the vulcanized oil present. The methyl cellulose solution was a 1% solution, so that the resultant dispersion or emulsion contained 50% solids.

The dispersion was stable and was readily dilutable with water. l

Example 3 A linseed oil product was pretreated with $02 and with sodium hydroxide, and vulcanized exactly as set out above in steps 1 to 9 inclusive of the illustrative process. 1800 gms. of the fully vulcanized linseed oil was placed into a Reed mixer (a type of kneading machine) and 54 gms. of a wetting agent manufactured by General Dyestuffs Corporation and described by the manufacturers as a product of the type of polyethyleneoxide condensation products, were added and kneaded into the batch. After the mass because homogeneous, 288 cc. of a 10% aqueous sodium hydroxide solution were added gradually, and the mixture worked until it was homogeneous, Then 180 cc. of a 10% aqueous solution of another wetting agent manufactured by E. I. Du Pont de Nemours & Co. and described by the manufacturers as a fatty alcohol sulphate (lauryl alcohol sulfate), was added, this being followed by addition of 1360 cc, of water.

An oil-in-water dispersion was secured which could readily be diluted with water. Under a microscope the particle size was found to be fairly small.

Example 4 300 gms. of a, linseed oil product treated in accordance with steps 1 to 9 inclusive of the illustrative process above were inserted into a small (laboratory size) Werner and Pfleiderer mixer (a type of kneading machine). 50 cc. of a 10% aqueous sodium hydroxide solution were added in one lot and the batch then worked until homogeneous, which required about one hour. Thereafter, 50 gms. of a 15% casein solution (the composition and preparation of which is mentioned below) was diluted with 250 cc. of water and this diluted solution added slowly into the mixture. After further working the mixture again became homogeneous and at that time cc. of water were also added.

A dipsersion of the oil-in-water type was secured, which diluted readily with water. It had a fairly large particle size.

The casein solution was prepared as follows:

150 lbs. of an emulsion stabilizer, manufactured by Casein Co. of America and described by the manufacturers as a water soluble casein material, were added to 850 lbs. of water at room temperature, with constant stirring. After standing for 30 minutes, 3 lbs. of ammonium hydroxide (28% NI-Is) were added and following this 1.5 lbs. each of two (Dow Chemical Co. casein protective agents of the type represented by the sodium salt of 2, 3, 4, G-tetrachlorophenol). The mixture was then heated in a steam-jacketed kettle to a temperature of F. and held there for 30 minutes with vigorous agitation. This produces an approximately 15% casein solution which was employed in the manner indicated above, the casein solution being used in the example at room tem-.

perature.

The dispersion products of the present invention may be used per se for various purposes or may be combined or mixed with other materials, such as other emulsions, for instance latex emulsions. Moreover, if desired, various other materials may be admixed with the fully vulcanized oil prior to forming the dispersion and/or prior to vulcanization. For example, resins may be present. In fact, highly advantageous properties are secured with an emulsion product according to the invention containing, in addition to the fully vulcanized oil, ,a resin, such as emulslonj varnish films.

product being in the nature of an emulsified varnish base, capable of yielding highly satisfactory Solvents may be added during or after emulsification. In the former case they may be workedinto the fully vulcanized product in the kneading machine or on the paint mill used for emulsification.

I claim 1. An oil-in-water dispersion the dispersed phase of which incorporates a fatty oil having a water soluble soap thoroughly dispersed therein, the cation of said water soluble soap being a member of the class consisting of alkali metals, ammonium and organic amines, said fatty oil being a heat bodied oil which is in a fully vulcanized state.

2. An oil-in-water dispersion the dispersed phase of which incorporates a fatty oil having a water soluble soap thoroughly dispersed therein, the cation of said water soluble soap being a member of the class consisting of alkali metals, ammonium and organic amines, said fatty oil being a heat bodied oil which is in a fully vulcanized state, and said water soluble soap is produced in situ during the preparation of the heat bodied oil, by water soluble compounds containing cations which form water soluble soaps with fatty acids. i

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,083,550 Auer June 15, 193"! 2,234,545 Auer Mar. 11, 1941 1,957,437 Auer May 8, 1934 1,963,065 Auer et a1 June 19, 1934 FOREIGN PATENTS Number Country Date 309,167 Great Britain Mar. 13, 1930 335,912 Great Britain Sept. 29, 1930 

